Ed, it's the spindle that's different size, so the ID is different.  OD is the same on all front wheel bearings.  

On 2010-10-21, at 12:00 AM, Automatic digest processor wrote:

> There seems to be only one brake disc  for all '80 to '85 model years, =
> but more than one wheel bearing style (up to some time in '83, and then =
> from mid '83 on.) I'm wondering why the same disc could house two =
> different wheel bearings.
> 
> I also noticed that the Bus Depot seems to list different chassis =
> numbers that correspond with the mid-year change of wheel bearings- they =
> list the same month and year, but different chassis numbers. It would =
> seem that if you're ordering early front wheel bearings from them, you =
> might want to cross reference with another vendor to see whether to =
> order early or late.

Cheers,    

Frank Condelli
Almonte, Ontario, Canada
'87 Westy & Lionel Trains (Collection for sale)
Frank Condelli & Associates - Vanagon/Vanagon Westfalia Service in the Ottawa Valley
Vanagon Stainless Steel Exhaust Systems
BusFusion a VW Camper camping event, Almonte, ON, June 10 ~ 13, 2010